STS Meeting Looks at New TAVR Device and Reviews Valve Procedure Rates in the UK

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A pair of studies describes early results with a novel, self-expanding aortic valve prosthesis as well as the evolution of transcatheter aortic valve replacement (TAVR) in the United Kingdom. The data were presented January 28, 2013, at the Society of Thoracic Surgeons Annual Meeting in Los Angeles, CA.

In the first study, researchers led by David M. Holzhey, MD, of Heart Center Leipzig (Leipzig, Germany), performed an interim analysis of 61 patients with severe aortic valve stenosis at high or extreme risk for surgical valve replacement. The patients received TAVR using the Engager aortic valve prosthesis (Medtronic, Minneapolis, MN) at 4 sites in Germany from September 2011 through May 2012.

The device, which is not approved currently in Europe or the United States, is a flexible prosthesis composed of 3 bovine pericardium leaflets sewn to a polyester sleeve and mounted on a compressible, self-expanding nitinol frame. A main feature of the valve is commissural support arms intended to release and engage against the sinuses, allowing for correct anatomical positioning and axial fixation, with the goal of minimizing paravalvular leakage.

Only Trace Leakage

For all attempted implantations (n = 60), the Engager prosthesis was positioned in the correct anatomical position without any conversions to surgery, second valve implantation, device malposition, aortic annular rupture, or coronary obstruction. At 30 days, all-cause mortality and major apical access site complications were 9.9% and 8.4%, respectively. On 30-day echocardiography, average mean gradient was 11.5 ± 5.0 mm Hg, with no patients experiencing greater than trace paravalvular regurgitation.

At 6 months, all-cause mortality was 16.9%, cardiovascular mortality was 11.9%, stroke was 5.5%, and new pacemaker requirement was 16.9% for AV block III and 15.5% for reasons other than AV block III.

“Early postoperative results support implantation success and valve safety,” the researchers conclude.

The mean age of the patients was 81.9, with more than half (62.3%) female. The majority (88.5%) were NYHA class III/IV; 52.5% had CAD and 49.2% PVD.

“The Engager was meant to reduce paravalvular leak by better engagement at the level of the annulus and better positioning,” Philippe Généreux, MD, of Columbia University Medical Center (New York, NY), explained in an interview with TCTMD. “The [lack of] paravalvular leak is a very good sign.”

Dr. Généreux noted that since the Medtronic CoreValve has shown a higher need for pacemaker implantation than the Sapien valve (Edwards Lifesciences, Irvine, CA), that and stroke incidence will be key endpoints to watch with Engager going forward.

Otherwise, “Everybody’s focusing on reducing paravalvular leak,” he said, calling that the “hot topic right now.” Dr. Généreux added that several companies are developing valves specifically designed to reduce such leakage. “There is a race at the moment,” he said, noting that many models are already available in Europe. “With the Medtronic valve, the problem was that the deployment was very difficult. Engager seems very easy, it sits well and seals better. And now they have a transapical way to do it.”

TAVR in the United Kingdom

In the second study, researchers led by Neil E. Moat, MBBS, of Royal Brompton Hospital (London, United Kingdom), used the National Institute for Cardiovascular Outcomes Research to analyze all aortic valve interventions between January 1, 2006, and January 1, 2011, in the United Kingdom.

The vast majority of patients (n = 35,406) underwent either surgical AVR or surgical AVR with CABG, while a minority (n = 1,620) underwent TAVR with either the Sapien or CoreValve devices. Surgical AVR procedures peaked in 2008 then declined slightly. TAVR was marked by steady growth, peaking in 2010 at just over 10% of all aortic valve interventions.

Aortic valve procedures increased by almost 100% in patients over age 80 (from 1,055 to 2,035 in 2010). This increase was due in equal parts to rises in TAVR and surgical AVR. Thirty-day and 1-year mortality were predictably higher in the TAVR cohort (table 1), but this decreased by more than half from 13.9% in 2007 to 6.2% in 2010.

Table 1. Clinical Outcomes

 

Surgical AVR

AVR + CABG

TAVR

30-Day Mortality

2.3%

4.5%

6.6%

1-Year Mortality

6.2%

10.4%

20.4%

30-Day Mortality in Patients > 80 Years

4.1%

6.3%

6.6%


The results provide “detailed insight into the evolution of aortic intervention during the introduction of [TAVR] and [the study] is relatively unique in capturing all interventional activity during this period in a defined population,” the researchers conclude.

Dr. Généreux noted that after establishment of a valve program, it is natural to see shifts in volume between surgical and transcatheter procedures. “The real question is: Is the patient best suited with this shift? I think yes, the patient will be more appropriately treated and [see] better outcomes,” he said.

Overall, Dr. Généreux commented, since the introduction of TAVR, the field has been moving in a fairly rapid manner to address the procedure’s shortcomings, but more issues remain. “The first one was vascular complications, which is almost over now with smaller devices. The stroke issue still remains at around 3% to 5%, but with new technologies and better implantation, this rate will decrease,” he said. “There is also need for pacemaker. It’s a bigger problem with Medtronic, maybe the Engager will help reduce it. The main issue, though, is durability, how long will it last? Now we have 5-year data. What is it [going to be] at 10 years?”

 

 


Sources:

1. Holzhey DM, Linke A, Treede H, et al. Intermediate follow-up results from the Engager multicenter European pivotal trial. Presented at: Society of Thoracic Surgeons 49th Annual Meeting; January 28, 2013; Los Angeles, CA.

2. Moat N, Cunningham D, de Belder M, et al. UK SATIRE: The combined UK cardiac surgical and TAVI registries: An analysis of activity, trends, and outcomes in 36,026 patients who underwent aortic valve intervention in the 5 years from 2006-2010. Presented at: Society of Thoracic Surgeons 49th Annual Meeting; January 28, 2013; Los Angeles, CA.

 

 

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Disclosures
  • Dr. Moat reports receiving honoraria/serving on the speakers bureau for Abbott Laboratories and serving as a consultant/advisory board member for Medtronic.
  • Drs. Holzhey and Généreux report no relevant conflicts of interest.

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